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| author | Christian Borntraeger <borntraeger@de.ibm.com> | 2018-06-21 14:49:38 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2018-06-25 10:07:12 +0200 |
| commit | 891f6a726cacbb87e5b06076693ffab53bd378d7 (patch) | |
| tree | b3fba7233d00da1bcb81a67ac04b73a997e40d16 | |
| parent | 7daf201d7fe8334e2d2364d4e8ed3394ec9af819 (diff) | |
| download | lwn-891f6a726cacbb87e5b06076693ffab53bd378d7.tar.gz lwn-891f6a726cacbb87e5b06076693ffab53bd378d7.zip | |
s390: Correct register corruption in critical section cleanup
In the critical section cleanup we must not mess with r1. For march=z9
or older, larl + ex (instead of exrl) are used with r1 as a temporary
register. This can clobber r1 in several interrupt handlers. Fix this by
using r11 as a temp register. r11 is being saved by all callers of
cleanup_critical.
Fixes: 6dd85fbb87 ("s390: move expoline assembler macros to a header")
Cc: stable@vger.kernel.org #v4.16
Reported-by: Oliver Kurz <okurz@suse.com>
Reported-by: Petr Tesařík <ptesarik@suse.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| -rw-r--r-- | arch/s390/kernel/entry.S | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index f03402efab4b..3891805bfcdd 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -1265,7 +1265,7 @@ cleanup_critical: jl 0f clg %r9,BASED(.Lcleanup_table+104) # .Lload_fpu_regs_end jl .Lcleanup_load_fpu_regs -0: BR_EX %r14 +0: BR_EX %r14,%r11 .align 8 .Lcleanup_table: @@ -1301,7 +1301,7 @@ cleanup_critical: ni __SIE_PROG0C+3(%r9),0xfe # no longer in SIE lctlg %c1,%c1,__LC_USER_ASCE # load primary asce larl %r9,sie_exit # skip forward to sie_exit - BR_EX %r14 + BR_EX %r14,%r11 #endif .Lcleanup_system_call: |